4A 8×12 Molecular Sieve Desiccant for Gas & Liquid Drying
4A 8×12 Molecular Sieve Desiccant for Gas & Liquid Drying - 100kg (220.46 lbs) Pallet (Vendor MOQ) is backordered and will ship as soon as it is back in stock.
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(Vendor MOQ) Buy 2+ 100kg pallets to save 10%, or 6+ 100kg pallets to save 20% — auto-applied at checkout.
| Qty | Discount |
|---|---|
| Buy 2 | 10% off each |
| Buy 6 | 20% off each |
4A 8×12 Molecular Sieve Desiccant from Delta Adsorbents is a high-capacity synthetic zeolite adsorbent used for moisture removal and selective molecular adsorption in industrial gases, liquids, compressed air, packaging, and process systems.
Its nominal 4-angstrom pore opening adsorbs water and other molecules small enough to enter the pore structure. Compared with 3A molecular sieve, the larger opening gives 4A broader adsorption capability, making it a versatile general-purpose molecular sieve for drying and purification applications.
Molecular sieve type: Sodium-form Type A synthetic zeolite
Particle size: 8×12 mesh spherical beads
Nominal pore opening: Approximately 4 Å
Minimum order: 100kg (approximately 220lb)
Bulk formats: Manufacturer drums and supersacks available by quotation
Where it fits
- Compressed-air drying: Deep moisture removal from compatible pneumatic and instrument-air systems.
- Industrial gas drying: Dehydration of natural gas, hydrogen, nitrogen, oxygen, synthesis gas, and compatible process gases.
- Gas purification: Adsorption of water, carbon dioxide, and selected small molecules from compatible gas streams.
- Saturated-hydrocarbon drying: Moisture removal from compatible hydrocarbon streams where broader adsorption than 3A is acceptable.
- Solvent and liquid drying: Removal of dissolved water from compatible liquids whose primary molecules are not undesirably adsorbed.
- Refrigerant drying: Moisture control in compatible refrigeration and closed-loop process systems.
- Paint and plastics processing: Water scavenging in compatible coatings, polymers, sealants, and formulated systems.
- Static packaging applications: Moisture control for pharmaceuticals, electronics, chemicals, and sensitive packaged products.
- Cryogenic processing: Water removal ahead of low-temperature equipment to reduce ice and hydrate formation.
Why choose 4A molecular sieve?
- General-purpose molecular adsorption: Provides broader adsorption capability than the smaller-pore 3A grade.
- High water capacity: Suitable for deep drying and low residual-moisture requirements.
- Approximately 4 Å pores: Adsorbs water and selected small molecules while excluding larger branched and aromatic compounds.
- Durable spherical beads: Designed to withstand handling, bed loading, pressure cycling, and regeneration.
- Regenerable media: Adsorbed moisture and compatible molecules can be removed through a properly designed regeneration cycle.
- Low-temperature effectiveness: Maintains strong water affinity under conditions where some other desiccants lose efficiency.
- Versatile industrial use: Suitable for regenerative dryers, fixed beds, static packaging, liquid drying, and process purification.
Typical specifications
| Product type | 4A molecular sieve adsorbent and desiccant |
|---|---|
| Structure | Sodium form of Type A synthetic zeolite |
| Chemical formula | Na12[(AlO2)12(SiO2)12] • nH2O |
| Form | Spherical beads |
| Particle size | 8×12 mesh |
| Nominal pore opening | Approximately 4 Å |
| Equilibrium water capacity | ≥22 wt.% at 25°C |
| Heat of adsorption | Approximately 1,800 BTU/lb of H2O |
| Bulk density | ≥0.70 g/mL (≥44 lb/ft³) |
| Crush strength | ≥30 N (≥7 lb) |
| Size qualification | ≥97% |
| Package moisture | ≤1.5 wt.% as shipped |
| Supplier | Delta Adsorbents |
Values shown are typical manufacturer properties for the 4A 8×12 beaded grade. Final acceptance requirements should be confirmed using the current technical specification and lot-specific COA.
What can enter a 4 Å molecular sieve?
| Molecule or material | General adsorption behavior |
|---|---|
| Water | Readily adsorbed and the primary target in most drying applications. |
| Carbon dioxide | Can be adsorbed, supporting purification of compatible gas and air streams. |
| Oxygen and nitrogen | Small enough to enter the pore structure under applicable operating conditions. |
| Straight-chain hydrocarbons | Certain straight-chain molecules may be adsorbed. |
| Branched-chain hydrocarbons | Generally too large to enter the nominal 4 Å pore structure. |
| Aromatic hydrocarbons | Generally excluded because of their larger effective molecular dimensions. |
Actual adsorption depends on molecular dimensions, temperature, pressure, concentration, competing compounds, and operating conditions.
4A vs. 3A molecular sieve
| Selection factor | 4A molecular sieve | 3A molecular sieve |
|---|---|---|
| Nominal pore opening | Approximately 4 Å | Approximately 3 Å |
| Adsorption range | Water plus selected small gases and straight-chain molecules | More selective primarily for water |
| Alcohol dehydration | May adsorb molecules or impurities that 3A excludes | Generally preferred for ethanol and methanol dehydration |
| General gas drying | Highly versatile general-purpose grade | Selected where tighter molecular exclusion is important |
| Typical applications | Compressed air, gas drying, CO₂ removal, refrigerants, packaging, solvents, paints, and plastics | Alcohol dehydration, unsaturated hydrocarbons, insulated glass, and selective water removal |
Choose the grade based on every molecule in the process stream—not water capacity alone.
4A vs. 13X molecular sieve
| Selection factor | 4A molecular sieve | 13X molecular sieve |
|---|---|---|
| Nominal pore opening | Approximately 4 Å | Approximately 10 Å |
| Selectivity | Excludes larger branched and aromatic molecules | Adsorbs a much broader range of larger molecules |
| Common emphasis | General drying and selected small-molecule adsorption | Broad gas purification, CO₂ removal, and larger-molecule adsorption |
| Potential product co-adsorption | Lower for molecules excluded by the 4 Å opening | Greater because of the larger pore opening |
Packaging & availability
| Format | Availability and use |
|---|---|
| 100kg minimum order | Standard Sorbents Direct minimum for this listing; suitable for vessel fills, production trials, and recurring industrial requirements. |
| 55lb (25kg) drum | Manufacturer-listed packaging suitable for smaller requirements and controlled manual loading; final configuration confirmed at quotation. |
| 330lb (150kg) drum | Manufacturer-listed industrial drum format; availability and fulfillment configuration confirmed at quotation. |
| Supersack | Bulk quantities filled to order specification and quoted based on required weight and delivery lane. |
- Minimum order: 100kg (approximately 220lb).
- Lead time: Typically 1-2 weeks, subject to stock, packaging, quantity, and destination.
- Freight: Parcel, pallet, or LTL service based on quantity and package configuration.
- Bulk requirements: Contact Sorbents Direct for supersack, recurring pallet, or truckload pricing.
System design considerations
Molecular-sieve performance depends on the incoming moisture and contaminant load, target outlet specification, flow rate, temperature, pressure, bed dimensions, cycle time, regeneration procedure, and allowable pressure drop.
- Moisture load: Determines how quickly the active bed approaches breakthrough.
- Adsorption temperature: Lower temperatures generally favor water adsorption.
- Operating pressure: Influences gas density, superficial velocity, adsorption behavior, and system capacity.
- Bed depth: Must provide sufficient mass-transfer-zone length and protection against early breakthrough.
- Flow velocity: Excessive velocity can increase pressure drop and reduce effective contact time.
- Competing molecules: Carbon dioxide and other adsorbable compounds may consume part of the available capacity.
- Regeneration quality: Heating, purge dryness, pressure, cooling, and cycle sequencing affect restored working capacity.
- Contaminants: Oils, particulates, heavy hydrocarbons, and reactive compounds may foul or damage the sieve.
Regeneration guidance
4A molecular sieve can be regenerated by removing adsorbed moisture and compatible adsorbates through a controlled thermal, purge, pressure-swing, or combined cycle. The correct procedure depends on the vessel, process stream, binder system, adsorbed compounds, and equipment limits.
- Follow the dryer or vessel manufacturer’s regeneration procedure.
- Increase temperature gradually to limit thermal stress and bead damage.
- Use sufficiently dry purge gas where thermal regeneration is employed.
- Maintain enough purge flow to carry desorbed moisture and contaminants out of the bed.
- Cool the regenerated bed under dry conditions before returning it to adsorption service.
- Avoid exposing hot regenerated sieve directly to humid ambient air.
- Track outlet dew point or contaminant breakthrough to evaluate cycle performance.
Regeneration note: Regeneration requirements may differ when the sieve has adsorbed carbon dioxide, hydrocarbons, solvents, or other process compounds in addition to water. Review the manufacturer and equipment requirements before establishing cycle conditions.
Handling & storage
- Store unopened molecular sieve in a clean, dry, well-ventilated location.
- Keep drums, bags, and supersacks tightly closed until use.
- Reseal partially used containers immediately because active sieve begins adsorbing ambient moisture upon exposure.
- Prevent unintentional contact with water and humid air.
- Protect the media from oils, dust, solvents, chemicals, and incompatible contaminants.
- Avoid breathing dust and use appropriate local exhaust ventilation where airborne material may be generated.
- Use safety glasses and a suitable NIOSH-approved dust respirator where required by the SDS and site risk assessment.
- Do not store supersacks outdoors, where ultraviolet exposure and weather can weaken the packaging.
- Handle used media based on the hazards of the substances it has adsorbed.
Important: Active molecular sieve releases heat when exposed to water. Direct contact with wetted active material may cause thermal injury. Review the current SDS before unloading, handling, spill cleanup, regeneration, removal, or disposal.
Why buy from Sorbents Direct?
Sorbents Direct helps industrial buyers compare molecular-sieve type, pore opening, bead size, adsorption requirements, packaging, freight, and regeneration needs before ordering.
- Industrial package quantities for production trials, vessel fills, and recurring requirements.
- Live or quoted freight support based on package size and delivery conditions.
- Manufacturer documentation including SDS, technical specifications, and lot-specific COA when available.
- Grade-selection assistance when comparing 3A, 4A, 5A, and 13X molecular sieves.
- Application support based on process chemistry, moisture target, flow, vessel dimensions, and regeneration method.
- Transparent pricing and fast quotation support for industrial buyers.
Documentation & technical support
The manufacturer Safety Data Sheet and technical specifications are available for this product. A lot-specific Certificate of Analysis may be requested for shipped material.
The SDS classifies the material as synthetic zeolite intended for adsorbent and desiccant use. It identifies dust-related eye, skin, and respiratory irritation precautions and notes that active media releases heat when exposed to water.
Visit our Documentation Center or contact Sorbents Direct to discuss your process stream, target outlet condition, flow rate, vessel dimensions, regeneration method, quantity, and documentation requirements.
Questions & answers
What is 4A molecular sieve?
4A molecular sieve is the sodium form of Type A synthetic zeolite. It has a nominal pore opening of approximately 4 angstroms and is used for water adsorption and selective removal of other sufficiently small molecules.
What does 8×12 mesh mean?
8×12 mesh describes the nominal bead-size range. The beads pass through an 8-mesh screen while being substantially retained by a 12-mesh screen, subject to the manufacturer’s size-qualification specification.
What is the pore size of 4A molecular sieve?
The nominal pore opening is approximately 4 angstroms.
What does 4A molecular sieve adsorb?
It readily adsorbs water and can also adsorb molecules such as carbon dioxide, oxygen, nitrogen, and certain straight-chain hydrocarbons. Larger aromatic and branched-chain hydrocarbons are generally excluded.
Can 4A molecular sieve be used for ethanol dehydration?
3A is generally the preferred molecular sieve for ethanol dehydration because its smaller pore opening excludes ethanol more selectively. Use 4A only when its broader adsorption behavior is acceptable for the process.
Can 4A molecular sieve remove carbon dioxide?
Yes. Carbon dioxide is small enough to be adsorbed by 4A molecular sieve. The resulting capacity and breakthrough behavior depend on moisture, temperature, pressure, concentration, and competing compounds.
Can this product dry compressed air?
Yes. 4A molecular sieve is widely used for compressed-air and gas drying where deep moisture removal is required.
Can it be used for solvent drying?
It may be used to dry compatible solvents, but the solvent and other compounds in the stream must be evaluated for possible adsorption within the 4 Å pore structure.
Can 4A molecular sieve be regenerated?
Yes. It can be regenerated through a properly designed thermal, purge, pressure-swing, or combined cycle. Regeneration conditions must account for all adsorbed compounds, not only water.
What is its equilibrium water capacity?
The manufacturer specification lists equilibrium water capacity at a minimum of 22 wt.% at 25°C. Dynamic working capacity in an actual system will be lower and process dependent.
What is the difference between equilibrium and working capacity?
Equilibrium capacity is measured under defined laboratory conditions. Working capacity is the usable amount adsorbed during an operating cycle and depends on temperature, pressure, flow, competing compounds, regeneration, and the permitted breakthrough level.
How should unused molecular sieve be stored?
Keep it tightly sealed in a clean, dry, well-ventilated location. Limit exposure to ambient air and do not store supersacks outdoors.
What package sizes are available?
The Sorbents Direct minimum order is 100 kg. Delta lists 55 lb and 330 lb drum configurations, with supersacks filled to order specification. Final fulfillment packaging is confirmed at quotation.
What is the typical lead time?
Typical lead time is approximately 1–2 weeks, subject to current inventory, quantity, packaging configuration, and shipping destination.
What documentation is available?
The manufacturer SDS and technical specifications are available. A lot-specific COA may also be requested for shipped material.

